Lens shade



March 17, 1931. T. 5:. HALLDOISON LENS SHADE Filed March 9. 1928 Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE THOMAS E. HALLIDORSON, OF CHICAGO, ILLINOIS LENS SHADE Application filed March 9, 1928. Serial No. 260,531.

This invention relates to lens shades to indicated in Fig. 1, less and less light will be be used with photographic or other apparaable to pass from surrounding objects into tus employing lenses for concentrating light, the open end of the cylinder 6 and, thus,

and for similar purposes; and it has for its through the lenses to the photographic plate.

object providing an improved shade for the lVhen the shade is in the position indicated ,in

lens so as to prevent light passing to the Fig. 2, the amount of light that passes from lens from objects outside the field to be objects outside the object being photographed photographed. One of the particular obwill be relatively much reduced. Thus, as

j ects of the invention is to provide shade will be understood, the size of the field to be 10 means which may be used to vary uniformly photographed may be gradually varied and, and continuously the field from which the at the same time, by merely shifting the light is passing to the lens so as to elimishade, the light from outside objects can be nate the stray outside light without affecteliminated without affecting the light from ing the field to be photographed, as that the field.

15 field may be varied. Other objects of the To assist in eliminating outside light as invention will be apparent from a considerathe size of the field to be photographed is vartion of the accompanying drawings and the led, a cap 10 may be used. This cap is arfollowing description thereof. ranged to slip over the end of the shade 7 and Of the drawings, Fig. 1 is aside elevation it has an opening 11 which is materially less of lens supporting means and shading means than the opening of the end of the shade. By 7 Which embody the features of my invention; placing this cap on the front end of the shade, Fig. 2 is a similar view of the apparatus with the amount of light passing from outside obthe shading means adjusted to reduce the jects is much reduced and can be reduced still amount of light compared with the arrangemore or entirely eliminated by sliding the ment of Fig. 1; and Fig. 3 is an end or shade forwardly so far as may be desired. front elevation of the apparatus. It will be understood also that various caps The shade is applicable to any uses of may be used with the openings 11 varying lenses or similar apparatus but, to illustrate as much as may be desired. While caps of my invention, I show it applied herein to a this nature have been used on lens cylinders,

photographic camera. In front of the camyet, by applying them to my slidable shade,

era, as is common, is mounted a board 5 for the effect of the shade in eliminating undesirsupporting the lens cylinder 6 and within able light may be continuously varied by this cylinder is mounted, in any suitable manvarying the opening in the cap applied to the ner the lenses of the camera. Any ordinary shade and shifting the shade to the most efshutter may be used, such as the shutter 12. fective position for the particular field and Slidably mounted on the camera, and encap. By the use of my shade the various circling the cylinder 6, is a lens shade 7. openings 11 may be so related that the maxi- This shade is preferably in the form of a mum amount of undesirable light which can cylinder and it is somewhat larger than the be eliminated by a cap with a large opening lens cylinder 6. The shade is slidably mountwill be fully as much as the minimum amount ed in any suitable manner. I prefer, for by a cap with a smaller opening; so that there this purpose, to provide rods 8, which are need be no steps in the graduation of the fixed to the lens board 5, and, by means of amount of light eliminated from the minithe cross rods 9, fixed to the lens shade 7 mum to the maximum.

and slidably mounted on the rods 8, the shade I claim as my invention:

can be shifted longitudinally with reference 1. A lens shade comprising a cylinder slidto the lens cylinder as much as may be necesably mounted 011 and encircling a lens holder,

sary. and a detachable cap mounted on the outer Obviously, as the lens shade is shifted outend of said cylinder, said cap having an openwardly from the camera from the position ing in its front wall.

2. In a camera a lens cylinder, a lens mounted in said cylinder, a shade cylinder enclosing and coaxial with said lens cylinder, means for supporting said shade cylinder, said shade cylinder being slidahly mounted on said supporting means, and a perforated cap detachably mounted on the outer end of said shade cylinder.

In testimony whereof, I hereunto set my hand.

THOMAS E. HALLDORSON. 

